Kegel Excercise balls are sex toys used to improve muscle tone in the vagina by strengthening the muscles. Most of the kegel balls, also known as ‘ben wa balls’, ‘oriental balls’ and ‘geisha balls’ contain smaller metal balls within the larger balls. These balls shake around and agitate the outer ball. When inserted in the vagina, this movement is created by movements of the body. The agitating balls send pulsations out and causes the vagina muscles to contract constantly, thereby excercising them.